The disclosure starts from a spring element according to the generic type described below. In addition, the present disclosure relates to a piston pump for delivering fluids having such a spring element.
Piston pumps are known from the prior art in various embodiments. For example, radial piston pumps comprising a plurality of pump elements for delivering pressure media are frequently used in vehicle brake systems, in which pumps at least one piston can be moved in a reciprocating manner by means of a cam. These so-called pump elements typically consist of a piston, a piston running surface frequently in the form of a cylinder, inlet and outlet valves, and sealing elements. The valves are used to control the fluid during the pumping movement of the piston. The inlet valve serves here to prevent the fluid from flowing back into the suction chamber during the compression phase, while the outlet valve prevents the fluid from flowing back from the pressure side into the interior of the pump. These valves are typically in the form of spring-loaded ball valves, the outflow channel for the outlet valve being formed by a so-called outlet valve cover and the pump cylinder, and the outlet valve being accommodated in the outlet valve cover. A constant throttling device is optionally integrated in the outflow channel.
For example, a piston pump for regulating the brake pressure in a hydraulic vehicle brake system is described in the published patent application DE 102 29 201 A1. The piston pump described comprises a pump housing, a pump piston mounted displaceably in the pump housing, an inlet valve, an outlet valve and a compression chamber arranged between the inlet valve and the outlet valve, which compression chamber is enlarged during a suction stroke of the pump piston and is reduced in size during a pressure stroke of the pump piston. A pressure chamber and a flexible wall dividing the pressure chamber from an opposing chamber are provided downstream of the outlet valve, a pressure in the pressure chamber acting upon the flexible wall and the flexible wall comprising an elastically resilient membrane mounted in an elastically yielding body. The outlet valve comprises a valve seat, a closing body and a closing spring which biases the closing body against the valve seat, which is provided in a fixed manner in the housing. The closing spring is implemented in the form of a leaf spring and bears with one end against the closing body and with another end against a body fixed to the housing. At least one opening is provided in the closing spring, which opening is preferably dimensioned sufficiently large that it has practically no throttling effect on the pressure medium, or sufficiently small that it has a constant throttling effect on the medium flowing through it.